My dog drinks a ton of water then throws up! Only nine pounds, he will drink any amount, and out of whatever. He throws up every day usually more than once. He used to be a stray. He is not very active, he prefers laying around. He gets VERY aggressive when it comes to water. If you catch him drinking out of the toilet or licking the shower he gets very angry and snaps which is unlike him, he is a pretty calm dog. This has been going on for a very long time (about a year or so). It suddenly came on, it wasn't very gradual. We tried the veterinarian and they thought it might be a parasite. They gave him meds but it didn't work.
We really don't have the money right now to take him in early for another appointment.